Definition of soil fertility

Soil fertility is a quantity that allows the soil to supply the needs required for optimal plant growth. To determine soil fertility including with respect to:
1. The degree of acidity of the soil (soil pH)
Used to measure the acidity of the soil pH tester (litmus paper). Fertile soil is usually a neutral pH (6.7 – 7). Acid soils can be neutralized by liming. While alkaline soil by using sulfur (sulfur).

2. The mineral content of the soil (nutrient)
An essential nutrient for plants such as Nitrogen (N), phosphorus (P), calcium (Ca), potassium (K), Magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), Copper (Cu), Zinc (Zn), and Chlorine (Cl).

3. Texture and depth of soil
The texture is smooth and rough soil particles. Soil particles composed of sand, clay and dust. When the earth element is said to be composed of sand rough texture. If the texture of the soil consists of very fine clay called. Soil texture is ideal for agricultural loam soil is sticky.

4. The composition of the soil
In an ideal soil composition consists of mineral material = 45%, = 5% organic matter, water and air between 20-30% from 20-30%. The content of water and air composition fluctuation means always changing.

5. topography
Topography is the slope of the land.